Employee Development Case Study Example | Topics and Well Written Essays - 1750 words

Employee Development - Case Study Example Learning is a ubiquitous phenomenon. Everyone learns on a daily basis. It is not possible to do a good job without learning. Learning is an ongoing lifelong process. No matter how good one is, he has scope to learn and do better. Learning can be done at close quarters or even from a distance. Peter Cresswell, general manager for consultancy services at Siemens, says, "Companies tend to think that they have got a unique problem and struggle with the idea of how to take it forward. But one of the benefits of training is that it allows you to apply a positive solution to any activity. Nothing is unique and nothing is insurmountable through either organizational or personal development" (Employee development coursework assignment). An organization keeps its performance in order by providing constant training to its staff and workers. Training is a learning process within a time frame. It raises the learning curve of an employee and keeps him attuned to the latest gadgets and services. There are many training models to choose from. An organization chooses the model that best suit it purposes. The training model must seek to enhance quality and it is in every employee's interest to develop his performance through training. Businesses producing exceptional results year after year have to thank their training programs for their employees. Training help forge good team work (Employee development coursework assignment). Diversity Issues Culturally diverse workforce makes challenging working environment. Cultural difference, ethnicity, nationalism, cultural identity, cultural taboos, cultural shock, cultural colliding, and diversity can cause difficult times in the work place. Diversity may not mean only racial differences but also differences in gender, age, sex, and religious beliefs. Diversity is the spice of life. It helps individuals and organizations by offering a wide range of options in different situations. Diversity is the combination of seven different colors that combine to give one color - white. However, diversity can also create rifts and class consciousness. Diversity does not mean only adversities. An enlightened management is capable of assimilating the diverse backgrounds and creates harmonious working conditions to achieve excellence. Globalization has been responsible for diversity in many corporations. It is mandatory for corporations to put in place appropriate training of its diverse personnel to

Supply Chain Design Paper Essay Example | Topics and Well Written Essays - 750 words

Supply Chain Design Paper - Essay Example This can be seen as both advantageous and disadvantageous. Advantages of Riordan’s manufacturing strategy Increases quality There is one major advantage with regard to this manufacturing strategy is the ability to increase the precision of the manufacturing process. Highly customised goods processes make it easier to increase quality as the employees will master the functions and ensure they are able to produce perfect products. Meeting individual needs of individual customers Customisation means that each customer can get a product that directly and closely meets their needs (Fogliatto & Silveira, 2011). However, firms involved in mass manufacturing find it harder to be able to customise their products to individual customer needs. However, with competition increasing and making it harder for firms to compete for the customers, it is necessary to increase the rates of satisfaction in customers. Mass customisation is an attempt to make mass production as customer customised as possible. It is looking at the needs of the customer as closely as possible and making sure that customers will get a product which is as close to their needs as possible. Mass customisation therefore increases customer satisfaction and this makes the firm more competitive in the market. Disadvantages Increased costs Customisation makes it is easier to deliver to the customers products they want but at an increased cost. In manufacturing, the biggest issue is that defects costs the firm a lot. It is the dream of every manufacturer to reduce the defect rate to as low as it can be possible so as to help the firm will not have losses. Every defective product is a loss to the firm because defective products cannot be sold. Mass customisation has the disadvantage of increasing the defect rates and therefore increasing the losses associated with the defects. Apart from increased defects rates making costs to go higher, mass customisation increases the cost of producing a single product ( Chandra & Kamrani, 2011). In other words, even in the absence of the issue of defects rates, customized manufacturing is not as cost effective as the mass production. Increasing the costs will mean that the firm will have to increase the prices of the product, and this may deny the firm the competitive edge in the market. Cannot be achieved wholly Mass customisation is usually a compromise that the firm has to make, and there is never a time where the firm will be able to fully customize the products. In regard to this, firm has to understand that not all products can be customised. In fact, as Blecke (2005) says, not all products need to be customized. Mass customisation only works where the product end customer is a mass buy. In cases where the end buyer is the individual, it becomes much harder to mass customize, and it becomes very impossible to meet the individual needs of millions of customers. Mass customisation is therefore an idea that is simple in theory and difficult in p ractice. In this regard, it is important to be able to understand that mass customisation may only be a hype which needs to be looked at critically. Flowchart Metrics to evaluate performance Issue Concern Impact Meeting customer needs It meets the customer needs High Cost management The costs associated with is are not prohibitive High Applicability It is applicable High Relevance It is relevant for the product High Market outlook It improves the market outlook Medium In the above metric, the most important thing is to determine whether the costs incurred in

George Orwell and William Golding Essay Example for Free

George Orwell and William Golding Essay Orwell and Golding use vastly different writing styles, but their message is the same that mankind is hopeless. Discuss this statement with reference to both Animal Farm and Lord of the Flies. Since the beginning of time man has struggled to comprehend the difference between good and evil. Our ancestors spent their lives looking for truth, yet none could be found. Is there indeed a good of all goods and an evil of all evils? The two are so similar, and yet so different. The truth is, no one being is perfect, nor were we created to be. No one thing can be the source of all evil, or the source of all good. Yet man battles with himself, to determine what is right. But what, then, is truly right? If there is an evil, then Humans should be deemed to be the most evil of all creatures. We are manipulative, egotistic and dominating. We have the urge to be the dominating force in the universe. We strive for superiority and aim for domination. Yet are such feelings to be considered wrong? Cannot they just be classified as instincts, which many other animals have? No, for we are indeed intelligent creatures and instead of exercising our superiority we should be learning of others greatness. We, as indeed intelligent beings should stray from the common selfishness and anger. Yet, they seem to be much easier to arouse, harder to abolish. In his novel Animal Farm, George Orwell portrays the animals with human-like feelings and emotions. He uses satire to demonstrate the full extent of human emotion. Though the story is about animals, there are very few who think it is just that. The satire gives the story enough appeal to readers, but the message rings as solemn as ever. George Orwell uses little dialogue, but describes the characters and situations with great detail, paying attention to their characters and emotions. It is easier to understand all the happenings, because the characters are animals. At the same time, when one compares them to humans, a striking similarity can be found. The book makes one think, and it hurts when one realizes that the story in the book is not far from our reality. It is a sad reality; however, it is necessary to acknowledge this for one to be able to  overcome it. George Orwells message is that humankind is hopeless. Perhaps we are, but a lost cause, we are not. For it is books like these, which help one to understand our faults so that one can correct them as best as one can. We were not created to be perfect, but we were also not created to be dominating and superior. All beings on this planet are created to be equals. Humans have forgotten such principles of nature. Humans battle to overcome cruelty. However, while we believe we have done so, the cruel, dominating and never ending cycle begins again. The truth is we are prisoners of our own characters, and perhaps that can never change. William Golding, the author of Lord of the Flies uses fictional portrayal of human emotional conflict to reach the reader. He takes a situation, which could quite realistically occur in life, and elaborates upon it. He uses complex vocabulary and original sentence structure to show the complexity and variation of human emotions. He uses the little boys as characters in the story to prove a very valid point. The fact that such small children can turn on each other so rapidly is a sobering thought. Golding shows, that no matter how good the intentions are at first, our inner feelings of selfishness can overcome us very easily, especially in a critical situation The book makes the reader contemplate their own actions in such a situation. Whereas as no one can be brutally honest with themselves, it is possible to relate to others. That is what Golding is trying to create. Regardless of whether they planned to do so or not, they will think, and perhaps that may bring us one step closer to understanding a very important character ourselves. Although their writing styles are prominently different, both George Orwell and William Golding show similar views on the human character. Their honest portrayal of humans as we are by nature leaves the reader thoughtful. So, are we then indeed bound for eternal struggle? Are we indeed as hopeless are the authors suggest? That is one question, which will not be answered with the advance in technology or by new scientific discoveries. We are our own  judges, but can we trust ourselves?

The Concept Of Collaborative Working Social Work Essay

The Concept Of Collaborative Working Social Work Essay Collaboration is a interprofessional process of communication and decision making that enables shared knowledge and skills in health care providers to synergistically influence the ways service user/patient care and the broader community health services are provided (Way et al, 2002). The development of collaborative working will necessarily entail close interprofessional working (Wilson et al., 2008). According to Wilson et al, (2008) and Hughes, Hemmingway Smith, (2005) interprofessional and collaborative working describes considering the service user in a holistic way, and the benefits to the service user that different organisations, such as Social Workers (SW), Occupational Therapists (OT) and District Nurse (DN) and other health professionals can bring working together can achieve. These definitions describe collaborative working as the act of people working together toward common goals. Integrated working involves putting the service user at the centre of decision making to m eet their needs and improve their lives (Dept of Health, 2009). This paper will focus first see why health care students learn about working together then reviewing government policy and how this can be applied in a Social Care context, then on influencing factors on the outcomes of collaborative working references within the professional literature, and finally, reviewing evidence on collaborative practice in health and social care. Learning to work collaboratively with other professionals and agencies is a clear expectation of social worker in the prescribed curriculum for the new Social Work Degree (DoH 2002). The reasons are plain: à ¢-  Service users want social workers who can collaborate effectively with others to obtain and provide services (Audit Commission 2002) à ¢-  Collaboration is central in implementing strategies for effective care and protection of children and of vulnerable adultsas underlined, respectively, by the recent report of the Victoria Climbià © Inquiry (Laming 2003) and the earlier No Secrets policies (DoH 2000) à ¢-  Effective collaboration between staff at the front-line is also a crucial ingredient in delivering the Governments broader goals of partnership between services (Whittington 2003). Experience is growing of what is involved in learning for collaborative practice. This experience promises valuable information for Social Work Degree providers and others developing learning opportunities but has not been systematically researched in UK social work programmes for a decade (Whittington 1992; Whittington et al 1994). The providers of Diploma in Social Work programmes (DipSW) represented an untapped source of directly transferable experience in this area of learning and were therefore chosen as the focus of the study. Making collaborative practice a reality in institutions requires an understanding of the essential elements, persistent and continuing efforts, and rigorous evaluation of outcomes. Satisfaction, quality, and cost effectiveness are essential factors on two dimensions: outcomes for patient care providers; and outcomes for patients. Ultimately, collaborative practice can be recognized by demonstrated effective communication patterns, achievement of enhanced patient care outcomes, and efficient and effective support services in place. If these criteria are not met, collaborative practice is a myth and not a reality in your institution. Simms LM, Dalston JW, Roberts PW. Collaborative practice: myth or reality? Hosp Health Serv Adm. 1984 Nov-Dec;29(6):36-48. PubMed PMID: 10268659. http://www.ncbi.nlm.nih.gov/pubmed Health care students are thought about collaboration so that they can see the unique contribution that each professional can bring to the provision of care in a truly holistic way. Learning about working together can help prevent the development of negative stereotypes, which can inhabit interprofessional collaboration. (Tunstall-Pedoe et al 2003) Health care students can link theory they have leant with practice and bring added value of successful collaborative practice. (www.facuity.londondeanery.ac.uk) Learning collaborative practice with other professionals is the core expectation in social work education both qualifying and post grad. Effective collaboration and interaction can directly influence a SU treatment, in a positive way, and the opposite can be said about ineffective collaboration that can have severe ramifications, which has been cited in numerous public inquiries. Professionals should also share information about SUs to keep themselves and their colleagues safe from harm. Working together to safeguard children states that training on safeguarding children and young people should be embedded within a wider framework of commitment to inter and multi-agency working at strategic and operational levels underpinned by shared goals, planning processes and values. The Children Act 1989 recognised that the identification and investigation of child abuse, together with the protection and support of victims and their families, requires multi-agency collaboration. Caring for People (DH, 1989) stated that successful collaboration required a clear, mutual understanding by every agency of each others responsibilities and powers, in order to make plain how and with whom collaboration should be secured. It is evident from the above that Government has been actively promoting collaborative working, and this is reflected in professional literature. Hence, the policy climate and legislative backdrop were established to facilitate inter-agency and intra-agency collaborati on. The stated aim has been to create high quality, needs-led, co-ordinated services that maximised choice for the service user (Payne, 1995). Political pressure in recent years has focused attention on interprofessional collaboration in SW (Pollard, Sellman Senior, 2005) and when viewed as a good thing, it is worthwhile to critically examine its benefits and drawbacks just what is so good about it. (Leathard, 2003). Interprofessional collaboration benefits the service user by the use of complementary skills, shared knowledge, resources and possibility better job satisfaction. Soon after the new Labour government in 1997 gave a powerful new impetus to the concept of collaboration and partnership between health professionals and services, they recognised this and there was a plethora of social policy initiatives official on collaborative working published. A clear indication of this can be found in NHS Plan (DH, 2000), Modernising the Social Services (DH, 1998a). Policies concentrat ed on agency structures and better joint working. This was nothing new, since the 1970s there has been a growing emphasis on multiagency working. 1974 saw the first big press involvement in the death of a child (Maria Coldwell) and they questioned why professionals were not able to protect children who they had identified as most at risk. The pendulum of threat to children then swung too much the other way and the thresholds for interventions were significantly lowered, which culminated with the Cleveland Inquiry of 1988 when children were removed from their families when there was little concrete evidence of harm (Butler-Sloss, 1988), with too much emphasis put on the medical opinion. An equilibrium was needed for a collaborative work ethic to share knowledge and skills and Munro (2010) states that other service agencies cannot and should not replace SWs, but there is a requirement for agencies to engage professionally about children, young people and families on their caseloads. T he Children Act 2004 (Dept of Health, 2004) and associated government guidance, introduced following the Public Inquiry into the death of Victoria Climbià © in 2000, including Every Child Matters (Dept of Health, 2003), were written to stress the importance of interprofessional and multiagency working and to help improve it. The failure to collaborate effectively was highlighted as one of many missed opportunities by the inquiry into the tragic death of Victoria Climbià © (Laming, 2003) and Baby Peter (Munro, 2009). There is an assumption that shared information is information understood problems with information sharing and effective commination are cited again and again in public enquiry reports Rose and Barnes 2008; Brandon et al, 2008). These problems can simply be about very practical issues, such as delays in information shearing, lost messages, names and addresses that are incorrectly recorded (Laming 2003 cited in Ten pitfalls and how to avoid them 2010) An explicit aim was to motivate the contribution of multiagency working. By 1997 Labour had been re elected and rolled out a number of studies into collaboration. These studies revealed the many complexities and obstacles to collaborative working (Weinstein, 2003). The main drivers of the governments health and social care policies were partnership, collaboration and multi-disciplinary working. One of the areas covered by Working Together to Safeguard Children 2010 (Dept of Health, 2010) stated that organisations and agencies should work together to recognise and manage any individual who presents a risk of harm to children. The Children Act 1989 (Dept of Health, 1989) requires multi-agency collaboration to help indentify and investigate any cases of child abuse, and the protection and support of victims and their families. It should be remembered that everyone brings their piece of expertise/ knowledge to help build the jigsaw (Working Together 2010) and to assess the service user i n a holistic way. Although the merits of collaboration have rarely been disputed, the risk of conflict between the professional groups remains. Some of the barriers to collaboration are different resource allocation systems, different accountability structures, professional tribalism, pace of change and spending constraints The disadvantages are if commissioning was led by health, an over-emphasis on health care needs, and inequities between patients from different practices There are challenges in terms of professional and personal resistance to change; it is difficult to change entrenched attitudes even through inter-professional education. Sometimes professionals disagree about the causes of and the solutions to problems, they may have different objectives because of different paradigms (Pierson M, 2010). There are also several concerns for SWs which include not knowing which assessments to use, appearing to be different or work differently from others in the team, not being taken seriously or listened to by colleagues and not having sufficient time or resources because of budget constraints (Warren, 2007). Some of the reasoning for this pessimistic mood is feelings of inequality and rivalries, the relative status and power of professionals, professional identity and territory. Different patterns of accountability and discretion between professionals, are all contributing factors to these feelings (Hudson, 2002). Thompson (2009) suggests that instead of the SW being viewed as the expert with all the answers to the problems, they should step back and look at what other professionals can contribute. Collaborative working offers a way forward, in which the SW works with everyone involved with the clients; carers, voluntary workers and other professional staff, to maximise the resources, thus giving an opportunity for making progress and affording the service user the best possible care. Weinstein, et al, (2003) stated that although there are problems with collaborative working, the potential positive outcomes out-weight the negatives. There could be a more integrated, timely and coherent response to the many complex human problems, fewer visits, better record keeping and transfer of information, and some reduction of risk; therefore the whole is greater than the sum of the parts. If SWs work in silos, working in a vacuum, they are unlikely to maximise their impact (Brodie, 2008). It is important to use collaboration and an interprofessional/multi agency working culture in Social Work in order that the most vulnerable service users receive the best possible assessments of their needs. The advantages are better understanding of the constraints of each agency and system overall, shared information on local needs, reduction in duplication of assessments, better planning, avoiding the blame culture when problems occurred and accessing social care via health less stigmatising. Greater knowledge of the SWs roles and responsibilities by other health care professionals will ensure that the SWs role is not substituted in assessment of the service users circumstances and needs (Munro, 2010). The Munro Report (2010) also states that if everyone holds a piece of the jigsaw a full picture is impossible until every piece is put together. Working together to Safeguard Children states a multi-professional approach is required to ensure collaboration among all involved, which may include ambulance staff, AE department staff, coroners officers, police, GPs, health visitors, school nurses, community childrens nurses, midwives, paediatricians, palliative or end of life care staff, mental health professionals, substance misuse workers, hospital bereavement staff, voluntary agencies, coroners, pathologists, forensic medical examiners, local authority childrens social care, YOTs, probation, schools, prison staff where a child has died in custody and any others who may find themselves with a contribution to make in individual cases (for example, fire fighters or faith leaders). In a study by Carpenter et al (2003) concerning the impact on staff of providing integrated care in multi-disciplinary mental health teams in the North of England, the most positive results were found in areas where services were fully integrated. There is much evidence to suggest that collaboration represents an ethical method of practice where differences are respected, but used creatively to find solutions to complex problems. In essence the service user should be cared for in a holistic approach and to achieve this collaboration is the answer. (1516) Professor Munro askes Some local areas have introduced social work-led, multi-agency locality teams to help inform best next steps in respect of a child or young person, including whether a formal child protection intervention is needed. Do you think this is useful? Do you have evidence of it working well? What are the practical implications of this approach? (http://www.communitycare.co.uk/Articles/2011/01/04/116046/munro-asks-frontline-workers-what-needs-to-change.htm)

Threatening Women of Homers Odyssey Essay example -- Homer, Odyssey E

The Threatening Women of Homer's Odyssey      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Aristotle called this poem 'a story of character' which is very true, as the analysis of people in the Odyssey id detailed and they are carefully depicted. Though the women still remain a fairly mysterious force that test Odysseus' determination for 'nostos' (hero's return home), requiring the man whose words are "like snowflakes" to use every trick he has to evade their threat, his civility not allowing him to strike them. In the Underworld, Agamemnon made it very clear in his enlightened state (consider the wiser Achilles who now regrets his noble death - "rather work the soil as a serf...than be King of all these lifeless dead" 11.490), as one of the dead that women "are no longer to be trusted". It is no co-incidence then that the female figures that Odysseus meets after this point are the most ferocious and dangerous. Both Scylla and Charybdis are hideous monsters, depicted as female, and so too are the tempting Sirens, all which test the hero. It is evidence that even after all his endeavours, Odysseus is still an Iliadic hero at heart, as he dons his armour uselessly to face Scylla's 12-headed threat and look at the good it does him ("Obstinate fool" 12.115). The actions of Odysseus' men result in him swimming in the sea and hanging over the swirling Charybdis, holding onto a fig tree ("clung like a bat" 12.433). Without warning from Circe, Odysseus would not have gone past the Sirens without doo m, since we see what the effect was without the wax in his ears ("longing to listen...set me free" 12.193). However, it is the humanoid females which are to add the most to the poem. The monsters test and batter the hero whilst the women test the man. To threaten Odysseu... ...ly). When he wishes to leave also, no effort is made by Circe to try and stop him unlike her counterpart above, Calypso ("do not stay on unwillingly" 10.484). Odysseus has been kept for the pleasure of Circe and he could have left at any time. This tarnishes our view of the hero's withstanding of the females' subtle threat.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Whether successfully or unsuccessfully, the female figure of the Odyssey all attempt to stop Odysseus on his inexorable journey home to his own female. Portrayed in contrasting depictions to draw out emphasis and focused details, the women and monsters threaten the hero in slightly different ways each time, testing Odysseus' flexibility and forcing him to break the Iliadic mould. Work Cited: Homer (Translated by Robert Fagles. Preface by Bernard Knox). 1996. The Odyssey. New York: Viking Penguin, div. of Penguin Books, Ltd. Threatening Women of Homer's Odyssey Essay example -- Homer, Odyssey E The Threatening Women of Homer's Odyssey      Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Aristotle called this poem 'a story of character' which is very true, as the analysis of people in the Odyssey id detailed and they are carefully depicted. Though the women still remain a fairly mysterious force that test Odysseus' determination for 'nostos' (hero's return home), requiring the man whose words are "like snowflakes" to use every trick he has to evade their threat, his civility not allowing him to strike them. In the Underworld, Agamemnon made it very clear in his enlightened state (consider the wiser Achilles who now regrets his noble death - "rather work the soil as a serf...than be King of all these lifeless dead" 11.490), as one of the dead that women "are no longer to be trusted". It is no co-incidence then that the female figures that Odysseus meets after this point are the most ferocious and dangerous. Both Scylla and Charybdis are hideous monsters, depicted as female, and so too are the tempting Sirens, all which test the hero. It is evidence that even after all his endeavours, Odysseus is still an Iliadic hero at heart, as he dons his armour uselessly to face Scylla's 12-headed threat and look at the good it does him ("Obstinate fool" 12.115). The actions of Odysseus' men result in him swimming in the sea and hanging over the swirling Charybdis, holding onto a fig tree ("clung like a bat" 12.433). Without warning from Circe, Odysseus would not have gone past the Sirens without doo m, since we see what the effect was without the wax in his ears ("longing to listen...set me free" 12.193). However, it is the humanoid females which are to add the most to the poem. The monsters test and batter the hero whilst the women test the man. To threaten Odysseu... ...ly). When he wishes to leave also, no effort is made by Circe to try and stop him unlike her counterpart above, Calypso ("do not stay on unwillingly" 10.484). Odysseus has been kept for the pleasure of Circe and he could have left at any time. This tarnishes our view of the hero's withstanding of the females' subtle threat.   Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚  Ã‚   Whether successfully or unsuccessfully, the female figure of the Odyssey all attempt to stop Odysseus on his inexorable journey home to his own female. Portrayed in contrasting depictions to draw out emphasis and focused details, the women and monsters threaten the hero in slightly different ways each time, testing Odysseus' flexibility and forcing him to break the Iliadic mould. Work Cited: Homer (Translated by Robert Fagles. Preface by Bernard Knox). 1996. The Odyssey. New York: Viking Penguin, div. of Penguin Books, Ltd.

The Afro-American Newspaper Goes to War :: United States History African American Essays

The Afro-American Newspaper Goes to War The Baltimore-based newspaper The Afro-American has been in existence since 1892 under the proprietorship of the Murphy family, and by the 1940’s had forged a place at the forefront of African-American journalism. The newspaper is still in business today and is online at www.afro.com. Founded by John Murphy, a former slave, the Afro-American has grown from a church weekly to one of the nations leading black newspapers. The newspaper has used it’s column inches to campaign for the civil rights of African-Americans throughout the 20th century, from opposing the persistence of racist â€Å"Jim Crow† laws in the South to defending eminent figures such as W.E. DuBois and Paul Robeson during the McCarthy-era anti-communism of the 1950’s.[1] During World War 2, when the U.S. military was still segregated along racial lines The Afro-American sent correspondents to cover the fighting alongside the various black American units that served in both the European and P acific theatres. These men and one woman were relaying to an audience of Maryland and Washington D.C. African Americans the roles fulfilled by black American troops, fighting in a segregated military abroad. The primary impact of black and white Americans serving together was to be felt socially in the post-war years. The Civil Rights movement that gained momentum in the 1950’s owed much to the fact that many people engaged in war work during the 1940’s, who in peacetime would never interact with one another on grounds of race, were challenged by their shared wartime experiences. â€Å"The common danger, the common foe and hardships of battle are bringing American troops closer together†¦Soldier after soldier has told me he can never be narrow-minded again after seeing such widespread human suffering.†[2] Ollie Stewart, correspondent for The Afro American, 1944 Compared with the quality of contemporary reports filed by â€Å"embedded† reporters in the 21st century US military, filtered by both the Pentagon and major media networks, some of the copy from the Afro correspondents is surprising given the circumstances under which it was filed. Despite the circumstances of war the reports filed by Afro correspondents used a number of means to convey the reality of service in a segregated military without alarming the wartime censors, and did so with deep insight, humour and graphic accounts of the full spectrum of roles fulfilled by black service personnel. The Correspondents. Correspondents for the Afro American.

Metals are electropositive chemical elements

Metals are electropositive chemical elements that are characterised by the following qualities: ductility, malleability, luster, opacity, and conductance of heat and electricity. They can replace the hydrogen of an acid and form bases with hydroxyl radicals. Density is defined as a material's mass divided by its volume. Metals typically have relatively high densities, particularly when compared to polymers. Often, materials with high densities contain atoms with high atomic numbers, such as gold or lead. However, some metals such as aluminum or magnesium have low densities. These metals are useful in applications requiring other metallic properties but in which low weight is also beneficial. Fracture Toughness can be described as a material's ability to avoid fracture, especially when a flaw is introduced. Glass, for example, has low fracture toughness (although it exhibits high strength in the absence of flaws). Metals typically have high fracture toughness. Metals can generally contain nicks and dents without weakening very much. They are also impact resistant. A football player relies on this fact to ensure that his facemask won't shatter. The roll cage on a racecar, for example, is created from steel. This steel should remain intact in a crash, protecting the driver. The ability of a material to bend or deform before breaking is known as plastic deformation. Some materials are designed so that they don't deform under normal conditions. You don't want your car to lean to the east after a strong west wind, for example. However, sometimes we can take advantage of plastic deformation. The crumple zones in a car absorb energy by undergoing plastic deformation before they break. Stress takes place when forces pull (this is known as tension), push (compression) or act in combination on a material. Once the force is applied, the material responds by distorting, counterbalancing the force. With a larger force, there will be a correspondingly greater distortion until the item breaks. Stress is the force applied per unit of cross-sectional area square to the force. This can be expressed mathematically as:: Stress (s) = Force / unit of area The metric system units for stress are Newton per square meter (N/m2) and imperial system units are pounds per square inch (psi). Strain is the amount the material deforms from the unloaded state when the force is applied. Its formula is: Strain (x) = Change in length / original length Since strain is a ratio of length divided by a length, it has no units. By the formula, we can see that it represents a proportional change in size. Deformation occurs when a force is applied to a metal. The metal is therefore strained. The greater the force – the more the deformation (strain). This relationship is recognised in Hooke's Law. Hooke's Law describes an elastic region where stress and strain are proportional (a straight line on a graph). In this region the metal acts like a spring and when the load is removed the deformation (strain) reduces and it returns to its original shape. If instead the load increases, the strain (deformation) rises and the metal undergoes uniform plastic deformation. The stress-strain graph is curved in this region. Eventually, a maximum stress is reached when the metal when the material reaches its limit of necking. Necking is localized thinning that occurs during sheet metal forming prior to fracture. The onset of localized necking is dependent upon the stress state which is affected by geometric factors. Finally, past the maximum stress point, a point is reached where the metal can no longer sustain the load and it yields. The behavior of metals under load is a result of their atomic arrangement. When a material is loaded it deforms minutely in reaction to the load. The atoms in the material move closer together in compression and further apart in tension. The amount an atom moves from its neighbor is its strain. As a force is applied the atoms change a proportionate distance. This model however, does not explain why there is sudden yielding. With most modern metals yielding usually occurs at about 1% of the theoretic strength of the atomic bonds. Many materials yield at about 0.1% of the theoretic strength. Rather, metals exhibit such low strengths because of imperfect atomic structures in the crystal lattices which comprise them. A row of atoms will often stop mid crystal, creating a gap in the atomic structure. These gaps act as dislocations, which are huge stress raising points in the metal. These dislocations move when the metal is stressed. A dislocation is defined as allowing atoms to slip one at a time, making it easier to deform metals. Dislocation interactions within a metal are a primary means by which metals are deformed and strengthened. When metals deform by dislocation motion, the more barriers the dislocations meet, the stronger the metal. The presence of dislocations in metal allows deformation at low levels of stress. However, eventually so many dislocations accumulate that insufficient atoms are left to take the load. This causes the metal to yield. Plastic deformation causes the formation of more dislocations in the metal lattice. This has the potential to create a decrease in the mobility of these dislocations due to their tendency to become tangled or pinned. When plastic deformation occurs at temperatures low enough that atoms cannot rearrange, the metal can be strengthened as a result of this effect. Unfortunately, this also causes the metal to become more brittle. As a metal is used, it tends to form and grow cracks, which eventually cause it to break or fracture. Atoms of melted metal pack together to form a crystal lattice at the freezing point. As this occurs, groups of these atoms form tiny crystals. These crystals have their size increased by progressively adding atoms. The resulting solid, instead of being a single crystal, is actually many smaller crystals, called grains. These grains will then grow until they impose upon neighbouring growing crystals. The interface between the grains is called a grain boundary. Dislocations cannot easily cross grain boundaries. If a metal is heated, the grains can grow larger and the material becomes softer. Heating a metal and cooling it quickly (quenching), followed by gentle heating (tempering), results in a harder material due to the formation of many small Fe3C precipitates which block dislocations. The atomic bonding of metals also affects their properties. Metal atoms are attached to each other by strong, delocalized bonds. These bonds are formed by a cloud of valence electrons that are shared between positive metal ions (cations) in a crystal lattice. These outer valence electrons are also very mobile. This explains why electrons can conduct heat and electricity – the free electrons are easily able to transfer energy through the material. As a result, metals make good cooking pans and electrical wires. In the crystal lattice, metal atoms are packed closely together to maximize the strength of the bonds. It is also impossible to see through metals, since the valence electrons absorb any photons of light hitting the metal. Thus, no photons pass through. Alloys are compounds consisting of more than one metal. Creating alloys of metals can affect the density, strength, fracture toughness, plastic deformation, electrical conductivity and environmental degradation. As an example, adding a small amount of iron to aluminum will make it stronger. Alternatively, adding some chromium to steel will slow the rusting process, but will make it more brittle. Some alloys have a higher resistance to corrosion. Corrosion, by the way, is a major problem with most metals. It occurs due to an oxidation-reduction reaction in which metal atoms form ions causing the metal to weaken. The following technique that has been developed to combat corrosion in structural applications: sacrificial anode made of a metal with a higher oxidation potential is attached to the metal. Using this procedure, the sacrificial anode corrodes, leaving the structural part, the cathode, undamaged. Corrosion can also be resisted by the formation of a protective coating on the outside of a metal. For example, steels that contain chromium metal form a protective coating of chromium oxide. Aluminum is also exhibits corrosion resistant properties because of the formation of a strong oxide coating. The familiar green patina formed by copper is created through a reaction with sulfur and oxygen in the air. In nature, only a few pure metals are found. Most metals in nature exist as ores, which are compounds of the metal with oxygen or sulfur. The separation of the pure metal from the ore typically requires large amounts of energy as heat and/or electricity. Because of this large expenditure of energy, recycling metals is very important. Many metals have high strength, high stiffness, and have good ductility. Some metals, such as iron, cobalt and nickel are magnetic. Finally, at extremely low temperatures, some metals and intermetallic compounds become superconductors. Ceramic: Ceramic materials are inorganic, nonmetallic materials, typically oxides, nitrides, or carbides. Most ceramics are compounds between metallic and nonmetallic elements in which the interatomic bonds are either totally ionic, or predominantly ionic but having some covalent character. While many adopt crystalline structures, some form glasses. The properties of the ceramics are due to their bonding and structure. The term ceramic comes from the Greek word keramikos, which means burnt stuff! This signifies that the desirable properties of these materials are typically achieved through a high-temperature heat treatment process. This process is called firing. Ceramics are often defined to simply be any inorganic nonmetallic material. By this definition, glasses are also ceramic materials. However, some materials scientists state that a true ceramic must also be crystalline, which excludes glasses. The term â€Å"ceramic† once referred only to clay-based materials. However, new generations of ceramic materials have tremendously expanded the scope and number of possible applications, broadening the definition significantly. Many of these new materials have a major impact on our daily lives and on our society. Ceramics and glasses possess the following useful properties: high melting temperature, low density, high strength, stiffness, hardness, wear resistance, and corrosion resistance. Additionally, ceramics are often good electrical and thermal insulators. Since they are good thermal insulators, ceramics can withstand high temperatures and do not expand greatly when heated. This makes them excellent thermal barriers. The applications of this property range from lining industrial furnaces, to covering the space shuttle, shielding it from high reentry temperatures. The aforementioned glasses are transparent, amorphous ceramics which are extensively used in windows and lenses, as well as many other familiar applications. Light can induce an electrical response in some ceramics. This response is called photoconductivity. An example of photoconductivity occurs in fiber optic cable. Fiber optic cable is speedily replacing copper for communications – optical fibers can transmit more information for longer distances, and have less interference and signal loss than traditional copper wires. Ceramics are also typically strong, hard, and durable materials. As a result, they are attractive structural materials. One significant drawback to their use is their brittleness. However, this problem is being addressed by the creation of new materials such as composites. While ceramics are typically good insulators, some ceramics can actually act as superconductors. Thus, they are used in a wide range of applications. Some (the good insulators) are capacitors, others semiconductors in electronic devices. Some ceramics are piezoelectric materials, which convert mechanical pressure into an electrical signal. These are extremely useful for sensors. For superconducting ceramics, there is a strong research effort to discover new high Tc superconductors and to then develop possible applications. Processing of crystalline ceramics is based on the basic steps which have been used for ages to make clay products. The materials are first selected, then prepared, formed into a required shape, and finally sintered at high temperatures. Glasses, on the other hand, are typically processed by pouring while in a molten state. They are then worked into shape while hot, and finally cooled. There are also new methods, such as chemical vapor deposition and sol-gel processing, currently being developed. Ceramics have a wide range of applications. For example, ceramic tiles cover the space shuttle as well as our kitchen floors. Ceramic electronic devices make possible high-tech instruments for everything from medicine to entertainment. There are also some special properties which a few ceramics possess. For example, some ceramics are magnetic materials and, as mentioned above, some have piezoelectric properties. The one major drawback of ceramics and glasses is that they are brittle. As mentioned above, certain types of ceramics possess superconducting properties at extremely low temperatures. For example, there are high-temperature superconducting ceramic materials that have recently been discovered. These materials exhibit virtually no electrical resistance below 100 degrees Kelvin. Also, these materials exhibit what is known as the Meissner effect. This means that they repel magnetic flux lines, allowing a magnet to hang in the space above the superconductor. An example of special group of crystalline ceramics is the group called Perovskites. They have captured the interest of geologists due to the information they can yield about Earth's history. The most intensely studied Perovskites at the present time are those that superconduct at liquid nitrogen temperatures. Ceramics were historically used for creating pottery and artwork, largely because the brittleness and difficulty of manufacturing ceramics restricted them from other uses until recently. However, the market requirement for microelectronics and structural composite components has risen, causing the demand for ceramic materials to likewise increase. Fiber-reinforced composites, an example of a modern ceramic application, are being created from ceramic fibers with extremely high stiffness, such as graphite and aluminum oxide. Polymers: Polymers are substances which contain a large number of structural units joined by the same type of linkage. They are any of many natural and synthetic compounds, usually of high molecular weight. They typically consist of up to millions of repeated linked units, each a relatively light and simple molecule. These substances often form into a chain-like structure. Some polymers have been around since the beginning of time in the natural world. For example, starch, cellulose, and rubber all possess polymeric properties. Man-made polymers, a relatively recent development, have been studied since 1832. However, the polymer industry today has is larger than the aluminum, copper and steel industries combined. Polymers have a huge range of applications that greatly surpasses that of any other class of material available to man. Current applications include adhesives, coatings, foams, packaging materials, textile and industrial fibers, elastomers, and structural plastics. Polymers are also widely used for many composites, electronic devices, biomedical devices, optical devices, and precursors for many newly developed high-tech ceramics (such as the fiber-reinforced composite mentioned at the end of the ceramic section). The word polymer literally has the meaning â€Å"many parts.† A polymeric solid material can be considered to be one containing many chemically bonded parts or units, themselves which are bonded together to form a solid. Polymers are typically good insulators. While a large variety of polymer applications were described above, two of the most industrially important polymeric materials are plastics and elastomers. Plastics are a large and varied group of synthetic materials. They are processed by forming or molding into shape. There are many types of plastics such as polyethylene and nylon. Polymers can be separated into two different groups depending on their behaviour when heated. Polymers with linear molecules are often thermoplastic. Thermoplastic substances soften upon heating and can be remolded and recycled. They can be semi-crystalline or amorphous. The other group of polymers is the thermosets. In contast to thermoplastics, these substances do not soften under heat and pressure and cannot be remolded or recycled. Instead, they must be remachined, used as fillers, or incinerated to remove them from the environment. Thermoplastics are typically carbon-containing polymers which are synthesized by addition or condensation polymerization. This procedure forms strong covalent bonds within the chains and weaker secondary Van der Waals bonds between the chains. Normally, the secondary forces can be easily overcome by thermal energy, which makes thermoplastics moldable at high temperatures. After cooling, thermoplastics will also retain their newly reformed shape. Common applications of thermoplastics include parts for common household appliances, bottles, cable insulators, tape, blender and mixer bowls, medical syringes, mugs, textiles, packaging, and insulation. Thermosets exhibit the same Van der Waals bonds that thermoplastics do. They also have a stronger linkage to other chains. Different chains together in a thermoset material are chemically held together by strong covalent bonds. The chains may be directly bonded to each other, or alternatively may be bonded through other molecules. This â€Å"cross-linking† between the chains is what allows the material to resist softening upon heating. Thus, thermosets must be machined into a new shape if they are to be reused or they can serve as powdered fillers. However, while thermosets are difficult to reform, they have many distinct advantages in engineering design applications. These include high thermal stability and insulating properties, high rigidity and dimensional stability, resistance to creep and deformation under load, and low weight. A few common applications for thermosets include epoxies (glues), automobile body parts, adhesives for plywood and particle board, and as a matrix for composites in boat hulls and tanks. The polymer molecule, a long chain of covalent-bonded atoms, is the basic building block of a plastic. Polymers are typically carbon based and have relatively low melting points. Polymers have a very wide range of properties that enable them to be extensively used in society. Some uses include car parts, food storage, electronic packaging, optical components, and adhesives. Synthetic fabrics are essentially man-made copies of natural fabrics. Synthetic fibers do not occur in nature as themselves. They are usually derivatives of petroleum products. Examples of common synthetic fabrics are polyester, spandex, rayon, and velcro. Recent technological developments have lead to electrically conductive polymers. The behaviour of semiconductors can now be achieved with polymeric systems. For example, there are semiconducting polymers which, when sandwiched between two electrodes, can generate light of any color. This technology has the potential of leading to OLED (organic light-emitting diode) flat panel displays. This display would be light in weight, have low power consumption, and perhaps be flexible. Liquid crystals are another example of polymeric materials. As the name suggests, a liquid crystal is a state of matter intermediate between a standard liquid and a solid. Liquid crystal phases are formed from geometrically anisotropic molecules. This typically means they are cigar shaped, although other shapes are possible. The polymer molecules have a certain degree of order in a liquid crystal phase. Take the simplest case, the Nematic phase, in which the molecules generally point in the same direction but still move around with respect to one another as would be expected in a liquid. However, under the influence of an applied electric field, the alignment of the polymer molecules gives rise to light absorption. Composites: Composites are materials, usually man-made, that are a three-dimensional combination of at least two chemically distinct materials, with a distinct interface separating the components. They are created to obtain properties that cannot be achieved by any of the components acting alone. In composites, one of the materials, called the reinforcing phase, is in the form of fibers, sheets, or particles. This material is embedded in the other materials, called the matrix phase. The reinforcing material and the matrix material can be metal, ceramic, or polymer. Typically, reinforcing materials are strong with low densities while the matrix is usually a ductile, or tough, material. The purpose of the composite, when it is designed and fabricated correctly, is to combine the strength of the reinforcement with the toughness of the matrix to achieve a combination of desirable properties not available in any single conventional material. The downside is that such composites are often more expensive than conventional materials. Some examples of current applications of composites include the diesel piston, brake-shoes and pads, tires and the Beechcraft aircraft in which 100% of the structural components are composites. A structural composite often begins with lay-up of prepreg. At this point, the choice of fiber will influence the basic tensile and compressive strength and stiffness, electrical and thermal conductivity, and thermal expansion of the final pre-preg material. The cost of the composite can also be strongly influenced by the fiber selected. The resin/fiber composite's strength depends primarily on the amount, arrangement and type of fiber (or particle) reinforcement in the resin. Typically, the higher the reinforcement content, the greater the strength. There are also some cases in which glass fibers are combined with other fibers, such as carbon or aramid, to create a hybrid composite that combines the properties of more than one reinforcing material. Additionally, the composite is typically formulated with fillers and additives that change processing or performance parameters. Integrating the ceramic, metallic, plastic and semiconductor materials is a necessary requirement to the fabrication of the micro-electronics package. This is an example of a composite system whose function is to provide interface between the central IC (Integrated Chip) and the other items on, for example, a PCB (printed circuit board). Semiconductors: There is a relatively small group of elements and compounds that has an important electrical property, semi-conduction, which makes them neither good electrical conductors nor good electrical insulators. Instead, their ability to conduct electricity is intermediate. These materials are called semiconductors, and in general, they do not fit into any of the structural materials categories based on atomic bonding. For example, metals are inherently good electrical conductors. Ceramics and polymers (non-metals) are generally poor conductors but good insulators. The semiconducting elements (Si, Ge, and Sn) from column IV of the periodic table serve as a kind of boundary between metallic and nonmetallic elements. Silicon (Si) and germanium (Ge), widely used elemental semiconductors, are outstanding examples of this class of materials. These elemental semiconductors are also known as Mono Semiconductors. Binary semiconductors are formed by a compound of two elements, normally an element from group III combined with an element from group V (such as CdS), or a element from group II combined with an element from group VI (such as GaAs). Tertiary semiconductors are formed by a compound of three elements. These semiconductors are typically compounds of elements from groups I, III and VI (such as AgInS) or elements from groups II, IV and V (such as ZnGeAs). All materials have energy bands in which their electrons can exist. In metals, as stated above, the valence band is partially-filled, and the electrons can move through the material. In semiconductors, on the other hand, there is a band gap that exists, and electrons cannot jump the gap easily at low temperatures. At higher temperatures, more of the semiconductor`s electrons can jump the gap. This causes its conductivity to go up accordingly. Electrical properties can also be changed by doping This too, is one of their great assets. Putting impurities in a semiconductor material can result in two different types of electrical behaviour. These are the so-called n (negative) and p (positive) type materials. Group V elements like arsenic added to a group IV element, such as silicon or germanium, to produce n-type materials. This occurs due to the extra valence electron in group V materials. On the other hand, group III materials like boron produce the p-type because they have only three valence electrons. When n-type material is connected to a p-type material, the device then exhibits diode behaviour. In other words, current can flow in one direction across the interface but not in the other. Diodes can act as rectifiers, but they have also led to the development of the transistor. A bipolar junction transistor (BJT) is a diode with an added third material which creates a second interface. While both npn or pnp types exist, their basic operation is essentially the same as two diodes connected to each other. With proper biasing of the voltages across each diode of the device, large current amplification can be produced. Today, metal oxide semiconductor field effect transistors (MOSFETS) have become widely used and have replaced the BJT in many applications. As a result, millions of transistors can be placed on a single silicon chip or integrated circuit. These IC chips have better reliability and consume less power than the large vacuum tube circuits of the past. The fabrication of electronic devices from the raw materials requires two major steps. The semiconductor is first melted, and a seed crystal is used to draw a large crystal of pure, solid semiconductor from the liquid. Wafers of the semiconductor are sliced and polished. Second, the circuit pattern is etched or deposited using a photolithographic process. The individual chips are finally sectioned from the initial wafer. Semiconductors experience covalent bonding. Their electrons are more tightly bound than the electrons in metals, but much more loosely bound than the electrons in insulators. The atoms in semiconductors are typically arranged in a crystal structure: a diamond-like tetrahedral (in which each atom is bonded to 4 others). Semiconductors are also typically semi-shiny. The intermediate ability of semiconductors to conduct electricity at room temperature makes them very useful for electronic applications. For example, the modern computing industry was made possible by the capability of silicon transistors to act as fast on/off switches. Electronic computing speed has greatly increased with the integrated circuit. For example, the cycle times of today's computers are now measured in nanoseconds. Opto-electronic (laser diode) research is extending the already huge rate at which information can be transmitted. Biomaterials: A biomaterial is any nondrug material that can be used to treat, enhance, or replace any tissue, organ, or function in an organism. The term biomaterial refers to a biologically derived material that is used for its structural rather than its biological properties. It also refers to any material, natural or man-made, that comprises whole or part of a living structure, or biomedical device which performs, augments, or replaces a natural function. A biomaterial can be a metal, ceramic, polymer or composite. They may be distinguished from other materials because they possess a combination of properties, including chemical, mechanical physical and biological properties, which allow them to be suitable for safe, effective and reliable use within a physiological environment. For example, collagen, the protein found in bone and connective tissues, can be used as a cosmetic ingredient. A second example is carbohydrates modified with biotechnological processes that have been used as lubricants for biomedical applications or as bulking agents in food manufacture. The performance of biomaterials depends on material properties, design, biocompatibility, surgical technique, and the health of patient. In particular, biocompatibility relies on the acceptance of the device by the body. Ideally, there should be no irritation, inflammation, or allergic response Both biomaterials and biomechanical expertise are needed to perform in vitro testing of spinal implants. Endo-vascular stents provide structural support vessels following angioplasty and other major medical procedures. After an angioplasty procedure, vessels can experience re-stenosis and eventually return to their original pre-operative diameter. In as many as 10% of the procedures, the vessels may even collapse immediately. To prevent the vessels from shrinking, endo-vascular prosthesis or stents are used. These stents are examples of biomaterials. Stents are tubular structures consisting of a spring, wire mesh or slotted tubes that are deployed inside the vessel. Depending on the design and intended use (coronary/ peripheral), they can range in diameter from several millimeters to many times that size. A biomaterial must be typically have the following properties: it must be inert or specifically interactive, biocompatible, mechanically and chemically stable (or biodegradable), processable (for manufacturability), have good shelf life, be nonthrombogenic (does not cause clot formation) if it is blood-contacting, and be sterilizable. There are examples of biomaterials and compatibility problems which arise from the materials not having the above properties. These include dialysis tubing made of cellulose acetate, a â€Å"commodity plastic†, which is known to activate platelets and blood complement. Additionally, Dacron, a polymer widely used in textiles, has been used in vascular grafts, but only gives occlusion-free service for diameters larger than 6 mm. Finally, commercial grade polyurethanes, initially used in artificial hearts, can be thrombogenic (they cause clot formation). There are many prominent applications of biomaterials used in the medical profession today. Biomaterials are used in orthopedics for joint replacements (hip, knee), bone cements, bone defect fillers, fracture fixation plates, and artificial tendons and ligaments. They are also used for cardiovascular vascular grafts, heart valves, pacemakers, artificial heart and ventricular assist device components, stents, balloons, and blood substitutes. Another application is in ophthalmics, for contact lenses, corneal implants and artificial corneas, and intraocular lenses. They can also have cosmetic applications, such as in augmentation mammoplasty. Finally, other applications include dental implants, cochlear implants, tissue screws and tacks, burn and wound dressings and artificial skin, tissue adhesives and sealants, drug-delivery systems, matrices for cell encapsulation and tissue engineering, and sutures. 2). The following paragraphs will provide an analysis of the modern pop can and the considerations taken by the manufacturer in its design. The overall design of the can has several advantages over another popular beverage container, the glass bottle. The pop can is inherently light weight and cheap due to the aluminum or steel alloys that are used in its creation. The cost of a can accounts for only about 4 cents of the price of a canned beverage. About 10 cents goes for advertising. The 12 ounces of beverage in the container typically costs less than a penny to produce. It is also not easily breakable, unlike glass. The shape of the can is easy to hold in the hand, making it much easier for a customer to use. The aluminum or steel alloys of the can also have the ability to undergo expansion without breaking the container. Thus, if a pop can is frozen, it will not explode, it will simply deform. Glass, on the other hand, would not as easily deform and would likely break in this situation. Pop cans are also allow cheaper packaging methods than bottles to be used. This is because the cans can come into contact with each other without breaking, unlike bottles. This allows many cans to be transported without the need for extensive protective barriers between the individual cans. An additional feature that allows the cans to be more easily transported and organised is the shape of the bottom and top of the can. Both the bottom and top have a lip. This lip protrudes upward from the top and downwards from the bottom. In other words, there is a indentation in both the top and bottom of the can, as shown in the following figure: The radii of the top and bottom lips are matched so that one can is able to be stacked on top of another can. In other words, the top lip of one can fits neatly into the bottom lip of the second can. This is shown in the following diagram. This stacking feature is not possible with bottles, since the bottom base of a bottle does not resemble its top spout. The pop-top soda, with their attached tab, can provide an excellent example of inherently safer design from everyday life. When soda in cans was first introduced, a separate device was required to open these cans, and the first â€Å"pop-tops† represented a major advance in convenience (and environmentalism). The initial pop-tops were scored tear strips in the can top with attached rings or levers to grasp and tear the metal tab from the can. The top was completely removed from the can once the tab was opened, and this top was then discarded. These tabs were therefore environmental hazards when discarded. Alternatively, some people would dispose of the tab by placing it into the can before drinking the soda. This caused the tab to occasionally be swallowed when drinking from the can, so it sometimes had to be surgically removed. The current design of the pop-top soda can, where the tab remains an integral part of the can after opening, represents an inherently safer design. While the tab can be detached by flexing it back and forth until the metal fails, this requires some additional effort to do. It is therefore easier to use the can safely. The procedure involved in creating pop cans will now be outlined. This procedure demonstrates some of the major components of the cans. Modern pop cans are made from either steel or aluminium using advanced engineering and sophisticated technology. There is a special grade of low-carbon steel is used for steel drink cans, which is coated on each side with a very thin layer of tin. This tin allows the surface to be protected against corrosion. It also acts as a lubricant while the can is being formed. In aluminium cans, the aluminium is alloyed with magnese and magnesium, providing greater strength and ductility. Aluminium alloys of different strengths and thickness are used for making the can body and the end. The reason that the alloy used from the end must be stronger than that used for the body will be described shortly. The steps involved in manufacturing cans are illustrated in a simplified way below: The aluminium or steel strip arrives at the can manufacturing plant in huge coils. A thin film of oil is then used to lubricate the strip. The strip is then fed continuously through a cupping press that blanks and draws thousands of shallow cups every minute. Each cup is pressed through a set of tungsten carbide rings. This ironing process redraws and literally thins and raises the walls of the cans into their final can shape. Trimmers are then used to remove the surplus irregular edge and cut each can to a precise, specific height. The excess can material is recycled. These trimmed can bodies are passed through highly efficient washers. They are then dried. As a result, all traces of oil are removed in preparation for coating internally and externally. The clean cans are coated externally with a clear or pigment base coat. This coat provides a good surface for the printing inks. The cans are then passed through a hot air oven to dry the lacquer onto the surface. Next, a highly sophisticated printer/decorator applies the printed design in up to six colours. A varnish is also applied. 9.A coat of varnish is also applied to the base of each can by a rim-coater. 10.The cans pass through a second oven which dries the inks and varnish. 11.The inside of each can is sprayed with lacquer. This special layer is to protect the can itself from corrosion and its contents from any possibility of interaction with the metal. 12.Once again, lacquered internal and external surfaces are dried in an oven. 13.The cans are passed through a necker/flanger. Here the diameter of the wall is reduced or ‘necked-in'. The top of the can is flanged outwards to accept the end once the can has been filled. 14.Every can is tested at each stage of manufacture. At the final stage it passes through a light tester which automatically rejects any cans with pinholes or fractures. 15.The finished can bodies are then transferred to the warehouse to be automatically palletised before dispatch to filling plant. The Can End 1.Can end manufacture begins with a coil of special alloy aluminum sheet. 2.The sheet is fed through a press which stamps out thousands of ends every minute. 3.At the same stage the edges are curled. 4.The newly formed ends are passed through a lining machine which applies a very precise bead of compound sealant around the inside of the curl. 5.A video inspection system checks the ends to ensure they are perfect. TAB.The pull tabs are made from a narrow width coil of aluminum. The strip is first pierced and cut and the tab is formed in two further stages before being joined to the can end. 6.The ends pass through a series of dies which score them and attach the tabs, which are fed in from a separate source. 7.The final product is the retained ring pull end. 8.The finished ends, ready for capping the filled cans, are packaged in paper sleeves and palletised for shipment to the can filler. As mentioned above, a printer/decorator is used in the manufacturing of cans to apply a printed design in up to six colours to the can body. A varnish is then applied. A varnish is a viscid liquid, consisting of a solution of resinous matter in an oil, or a volatile liquid, typically laid on work with a brush. Once it is applied, the varnish soon dries, either by evaporation or chemical action, and the resinous part forms thus a smooth, hard surface, with a beautiful gloss, capable of resisting, to a greater or less degree, the influences of air and moisture. The varnish therefore improves the appearance of the printed design on the can. It also increases the durability of the design by ensuring that it is more resistant to the wearing effects of the elements. This can be readily observed through common experience. Even old, used pop cans retain their printed designs very well, despite being subjected to the elements such as moisture or air. Bottles, on the other hand, typically have paper labels attached with glue. This requires glue and paper. These bottle labels also do not possess the glossy sheen of the pop can design. Finally, they are more easily susceptible to the influences of the elements, particularly air and moisture. For example, placing a glass bottle and its label in water will cause the label to saturate with water. This degrades the legibility and appearance of the label, and greatly increases the chance that it will tear or fall off the bottle. In contrast, placing a pop can in water has no effect on the legibility, appearance, or durability of the printed design. The base-coater gives the can an exterior coat to enable the printing colours to fix properly (the base coat is sometimes The of the pop can is a separate piece to allow filling by the beverage maker prior to the top being installed. It can now be revealed why bottled beer and beer from a tap tastes different from beer in a can. Be forewarned: if you're a six-pack enthusiast, you're not going to like the explanation. When you sip a can of your favorite brew, you are savoring not only fermented grain and hops but just a hint of the same preservative that kept the frog you dissected in 10th-grade biology class lily-pad fresh: formaldehyde. What is formaldehyde doing in beer? The same thing it's doing in pop and other food and drink packaged in steel and aluminum cans: killing bacteria. But not the bacteria in the drink, the bacteria that attacks a lubricant used in the manufacture of the can. Notre Dame's Steven R. Schmid, associate professor of aerospace and mechanical engineering, is an expert in tribology – the study of friction, wear and the lubrication – applied to manufacturing and machine design. The co-author of two textbooks, Fundamentals of Machine Elements and Manufacturing Engineering and Technology (considered the bible of manufacturing engineering), Schmid has conducted extensive research on the manufacturing processes used in the production of beverage and other kinds of cans. Schmid explains that back in the 1940s, when brewers and other beverage makers began putting drinks in steel (and, later, aluminum) cans, the can makers added formaldehyde to a milk-like mixture of 95 percent water and 5 percent oil that's employed in the can manufacturing process. The mixture, called an emulsion, bathes the can material and the can-shaping tooling, cooling and lubricating both. Additives in the oil part are certain bacteria's favorite food. But if the bacteria eat the emulsion, it won't work as a lubricant anymore. So can makers add a biocide to the emulsion to kill the bacteria. Before a can is filled and the top attached, this emulsion is rinsed off, but a small residue of the oil-water mixture is inevitably left behind, including trace amounts of the biocide. The amounts remaining are not enough to be a health hazard, but they are enough to taste, and the first biocide used back in the 1940s was formaldehyde. In the decades since, can makers have devised new formulas for emulsions, always with an eye toward making them more effective, more environmentally friendly and less costly. But because formaldehyde was in the original recipe, people got used to their canned Budweiser or whatever having a hint of the famous preservative's flavor. For this reason, Schmid says, every new emulsion formula since then has had to be made to taste like formaldehyde, â€Å"or else people aren't going to accept it.† Extensive tests are run to make sure the lubricant and additives taste like formaldehyde. â€Å"It's not that it tastes okay. It's just what people are used to tasting,† he says. (Miller Genuine Draft and similar brews, Schmid says, use biocides that have no flavor.) The formaldehyde flavor legacy is one little-known aspect of can-making. Another involves the smooth coating applied to the inside of cans. The rinse cycle that attempts to wash off the emulsion also aims to remove particulate metal debris that forms on the metal's surface during the bending and shaping of a can. Like the emulsion, some of the microscopic debris always remains after rinsing. Unlike the emulsion, it can be dangerous to swallow. To keep powdered metal out of a can's contents, Schmid says, manufacturers spray-coat the inside with a polymer dissolved in a solvent. When the can is heated, the solvent boils away, leaving only the protective polymer coating. The coating not only plasters any microscopic debris to the can wall and away from the food, it keeps the food from interacting with can material, an especially important consideration with steel cans. â€Å"Say you've got tomato soup in this steel can. You don't want that acidic soup corroding your can. It would kill your can, and the can would adulterate your food,† Schmid says. â€Å"It's also why you're advised that when you go camping and you have Spaghettios you don't cook them in the can, because the polymer will degrade and you're going to be eating polymer.† (Industry sources tell Schmid that the typical consequences of such a culinary blunder are headaches and constipation.) Schmid says can manufacturers are forever searching for ways to improve efficiency in their struggle to stay price competitive with plastic and glass bottles. A single can-tooling machine can form 400 cans a minute. In a typical process, all but the top is shaped during a single stroke through a disk of aluminum or steel. The top, seamed on after filling, is made of a more expensive aluminum alloy, rich in magnesium. The added ductile strength of the magnesium is necessary so another machine can mash down a pillar of the metal to form the rivet that attaches the pop top. Today's beverage cans are â€Å"necked† near the top for a reason. The narrower-diameter means less of the expensive lid alloy is needed. It saves a minuscule fraction of a cent per can, but it adds up, Schmid says. â€Å"In this country alone we use about a can per person per day, so you have to make 250 million cans per day. It's an amazing thing to watch these machines kick out these cans.† Rivet is likely a separate part from the tab. It should be strong enough to attach the tab to the can and to ensure that it does not break when the can is opened. Lip on top of can prevents liquid from flowing down the side of the can. Bottom is indented to enable stacking even when the tab has been opened. The indent provides the necessary room for the open tab. For recycling purposes, pop cans can be neatly compacted flat, and are easy to transport using a wide range of containers. Rivet is a separate piece which connects the tab to the can top. Top of the pop can is stamped with words such as â€Å"recyclable† and â€Å"return for refund†. Thus, the alloy of the top must be soft enough to allow this stamping to occur. Aluminum costs more than steel, and the price has been rising. Steel â€Å"minimills† now have continuous casting processes that make sheet steel thin enough to form seamless cans. And there is competition from other materials as well. â€Å"We h ave to find ways to make cans lighter and lighter to keep fending off polymers, steel and glass. Lighter cans means lower prices to the consumer, who's then more likely to buy cans off the grocery shelf instead of two-liter bottles or glass.† ALCOA's answer is lightweighting, designing cans to use the thinnest aluminum possible within the constraints of strength and appearance. In 1993, Americans recycled 59.5 billion aluminum cans, 3 billion more than in 1991, and raised the national aluminum can recycling rate to 2 out of every 3 cans. Aluminum can recycling saves 95% of the energy needed to make aluminum from bauxite ore. Energy savings in 1993 alone were enough to light a city the size of Pittsburgh for 6 years. Special pallets and stacking techniques are used to protect can bodies from crushing stresses and to enable quick and efficient loading into the filling machine line. The first beverage can, filled by a brewer in Newark, New Jersey in 1935, weighed three ounces. Today, an aluminum beverage can weighs one half ounce – 600% less than the original beverage can. Can manufacturers strive to do even better through a process called â€Å"light weighting†-the use of lighter can ends and thinner body walls. Using less material at the beginning of the manufacturing process results in a more effective means of creating safe, reliable, performance-driven packaging. This results in less waste once the packages' contents have been consumed. It also saves manufacturers money – an added incentive. 3). The diameter of the bar is 12.7 mm. Its radius is half the diameter. Therefore, its radius can be calculated to be (12.7 mm)/ 2 = 6.35 mm. By applying the conversion factor that 1000 mm = 1 m, this radius can also be expressed as (6.35 mm) * (1 m / 1000 mm) = 6.35 x 10-3 m. The bar has a cross-sectional area given by the following formula: Cross-sectional area = ?r2 where r is the radius of the steel bar. Using this formula, the cross-sectional area of the bar can be calculated to be: Cross-sectional area = ?(6.35 x 10-3 m)2 Cross-sectional area = 1.266768698 x 10-4 m2 (Cross-sectional area = 1.27 x 10-4 m2 when significant figures are applied). Gravity applies a force to the bar proportional to the bar's mass. This force is given by the formula: Force due to Gravity = (Mass of object) * (Acceleration of Gravity) If we assume that the steel bar is located at the surface of the earth, the acceleration of gravity is approximately 9.8 m/s2 at this elevation. Therefore, the force applied to the bar by gravity can be calculated to be: Force due to Gravity = (7000 kg) * (9.8 m/s2) Force due to Gravity = 68600 kg*m/s2 (Force due to Gravity = 70000 kg*m/s2 when significant figures are applied) The stress placed on the bar is given by the following formula: Stress = (force) / (unit area) Therefore, the stress placed on the bar can be calculated to be: Stress = (68600 kg*m/s2) / (1.266768698 x 10-4 m2) Stress = 541535326.2 kg/(m*s2) (Stress = 500000000 kg/(m*s2) when significant figures are applied) The steel bar has a modulus of elasticity of 205,000 Mpa. 1 Pa is defined to be equal to 1 kg/(m*s2). Using the conversion factor that 1 x 106 Pa = 1 Mpa, 1 Mpa is defined to be equal to 1 x 106 kg/(m*s2). We can therefore express the modulus of elasticity of the steel bar in Pa as (205,000 Mpa) * (1 x 106 Pa / 1 Mpa) = 2.05 x 1012 Pa. The strain experienced by the steel bar is the fractional deformation it undergoes when a stress is applied. This strain can be represented mathematically by the following formula: where l represents the length of bar, and ?l represents the change in length of the bar due to the applied stress. The elastic region of the stress-strain curve refers to the portion of the curve in which an increase in stress will cause a linearly proportional increase in strain. Within this elastic region, removal of the stress will cause the strain to be reduced to zero as well. In other words, the material is not permanently deformed, and removal of the stress causes the material to return to its original dimensions. The strain is therefore reversible, or elastic. In the elastic region, therefore, stress and strain can be related by a proportionality coefficient. This proportionality coefficient relating the reversible strain to stress in the elastic region of the stress-strain curve is known as the modulus of elasticity. This modulus of elasticity can be represented mathematically as: Modulus of Elasticity = (Elastic Stress) / (Unit Strain) This equation can be rearranged to solve for the unit strain. This rearranged equation is expressed as: Unit Strain = (Elastic Stress) / (Modulus of Elasticity) Assuming the stress applied to the bar is small enough to ensure that the bar is still operating in the elastic region of the stress-strain curve, we can use the above equation to determine how much the bar will be strained by the load. Mathematically, this solution takes the following form: Unit Strain = (541535326.2 kg/(m*s2)) / (2.05 x 1012 Pa) Unit Strain = (541535326.2 kg/(m*s2)) / (2.05 x 1012 kg/(m*s2)) Unit Strain = 2.641635738 x 10-4 (Unit Strain = 3 x 10-4 when significant figures are applied) This strain is unitless because it represents the fractional deformation of the bar when the stress is applied.